Stapel, R. J.  (2020).  Ordinations of priests in the medieval diocese of Utrecht (1505-1518). IISH Data Collection. Verkregen van https://hdl.handle.net/10622/IEYIUX

Stapel, R. J.  (2016).  Priest-brethren in the Utrecht bailiwick, their superiors and their ties to the community. In U.  Arnold (Red.), Priester im Deutschen Orden. Vorträge der Tagung der Internationalen Historischen Kommission zur Erforschung des Deutschen Ordens in Wien 2012 (pp. 61?73). Weimar: VDG.

Stapel, R. J.  (2014).  Priests in the military orders. A prosopographical survey of the priest-brethren in the Utrecht bailiwick of the Teutonic Order (1350-1600). In K.  Toomaspoeg (Red.), H.  Houben (Vert.), Analecta Theutonica. Studies for the History of the Teutonic Order (Vol. 1, pp. 99?149). Galatina: Congedo. Verkregen van https://pure.knaw.nl/admin/files/1011327/Stapel_Priests_in_the_military_orders_Analecta_Theutonica_1_2014_proofreading_adjusted.pdf